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Insulation Properties and Degradation Mechanism for XLPE Subjected to Different Aging Periods

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CSEE Journal of Power and Energy Systems 2023年第5期9卷 1959-1967页

作者： Qian Wang Rui Liu Sichen Qin Xi chen Zicai Shen Zhe Hou zeli.Ju the Department of Electrical Engineering Xi’an University of TechnologyXi’an 710048China the Beijing Institute of Spacecraft Environment Engineering Beijing 100094China the State Grid Shaanxi Electric Power Research Institute Xi’an 710100China

Due to its excellent insulation and mechanical properties,cross-linked polyethylene(XLPE)is widely used as the insulation candidate of power cables in power transmission and distribution ***,its performance can be affected due to various stresses,which endangers safe operation of the power system in *** this paper,dielectric and insulation properties of XLPE materials of 110 kV cables with the service lives of 0,15,and 30 years were tested and *** show that with increase of service life,dielectric loss caused by the polarization process increases significantly,and dielectric strength decreases as *** frequency breakdown field strength and crystallinity decrease significantly,and carbonyl index *** degradation process of XLPE can be divided into two stages:the structure of the crystalline region of the original sample is relatively complete,and loss can be almost *** long-term service,the crystallization region is destroyed,and thermal oxygen reaction *** force is weakened,which makes breakdown easier to ***,there is no direct relation between the carbonyl index and macroscopic *** paper reveals the deterioration law of the XLPE cable insulation,which provides a theoretical basis for evaluating cable aging condition and is of great significance to improve cable operation safety and maintenance quality.

关键词： Crosslinked polyethylene dielectric properties insulation performance microstructure power frequency breakdown

Interfacial space charge characteristic of PPLP insulation for HVDC cables

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High Voltage 2020年第5期5卷 628-635页

作者： Xuefeng Zhao Lu Pu Zhiqiang Xu George chen Wei Duan Haofei Sun zeli.Ju Shannxi Electric Power Research Institute Xi'anShannxiPeople's Republic of China School of Electronics and Computer Science University of SouthamptonSouthamptonUK

High-voltage DC(HVDC)cables show more efficiency than high-voltage AC cables over the long distance power transmission and have attracted significant attention recently due to rapid developments in off-shore wind *** laminated paper(PPLP)insulation based HVDC cables have provided a reliable operation for many years and are the highest voltage level in operation at the *** this study,the authors intend to understand the electrical performance of PPLP insulation system by examining space charge in detail,especially at the *** has been found that the interface between polypropylene and Kraft paper acts as trap for charge carriers,resulting in an optimal electric field distribution in PPLP insulation *** optimal electric field distribution enhances overall electrical performance of PPLP insulation,including higher dc breakdown strength and lower electrical conductivity.

关键词： PPLP insulation charge

Metamorphic Characteristics and Tectonic Implications of the Kadui Blueschist in the Central Yarlung Zangbo Suture Zone,Southern Tibet

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Journal of Earth Science 2018年第5期29卷 1026-1039页

作者： Guangming Sun Xu-Ping Li WenYong Duan Shuang chen zeli.Wang Lingquan Zhao Qingda Feng Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Minerals Shandong University of Science and TechnologyQingdao 266590China Institut fur Geologie Mineralogie und GeophysikRuhr-UniversitatBochum 44780Germany Center of Hydrogeology and Environmental Geology Survey China Geological SurveyBaoding 071051China

The Kadui blueschist is located in the central section of Yarlung Zangbo suture zone （YZSZ）, southern Tibet, and has been subjected to the subduction of the Neo-Tethyan Ocean below the Asian Plate and provides important clues for better understanding the evolution of the India-Asia convergence zone. In this paper, the systematical petrographic and mineral chemical studies were carried out on the Kadui blueschist, which reveal a mineral assemblage of sodic amphibole, chlorite, epidote, albite and quartz with accessory minerals of titanite, calcite and zircon. Electron microprobe analyses demonstrate that amphibole shows zoned from actinolite core to ferrowinchite/riebeckite rim composition indicating that the sodic amphibole has formed during a prograde metamorphic event. The protolith of the blueschist is an intermediate-basic pyroclastic rock. The calculated pseudosection indicates a clockwise P-T path and constrains peak metamorphic conditions of about 5.9 kbar at 345 ℃. This condition is transitional between pumpellyite-actinolite, greenschist and blueschist facies with a burial depth of 20-22 km and a thermal gradient of 15-16 ℃/km. This thermal gradient belongs to high pressure intermediate P/T facies series and is possibly related to a warm subduction setting of young oceanic slabs. Our new findings indicate that the Kadui blueschist in the central part of YZSZ experienced a rapid subduction and exhumation process as a response to a northward subduction of the Neo-Tethyan oceanic lithosphere during the initial India-Asia collision stage.

关键词： Kadui blueschist metamorphism P-T conditions accretionary complex southern Tibet.

Influence of Different Connection Types on Mechanical Behavior of Girder Trusses

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Journal of Bioresources and Bioproducts 2019年第2期4卷 89-98页

作者： zeli.QUE Tongyu HOU Yifan GAO Qicheng TENG Qiuyun chen Changju WANG cheng CHANG Department of Wooden Structure Construction Engineering Nanjing Forestry UniversityNanjing 210037China

The static test of two single light wood trusses and two girder trusses were carried out to explore theperformance enhancement effect of girder trusses and the influence of different connection types on the mechanicalbehavior, which was studied through the comparison of the test results of four trusses. It is found that the girder trussescan show better load-carrying capacity and anti-deforming ability compared with which simply increases the cross-sectionsize of the members. Because of the advantage of the connection materials and the non-fastening connection mechanism,the wood pin-connected truss has more ultimate bearing capacity which is 2.6 times of single truss, and better deformationresistance which is only 66.2% of the nailed one’s creep value.

关键词： girder truss multiple combination connection node design static load test wood pin

Sirolimus eye drops inhibit acute alkali-burn-induced corneal neovascularization by regulating VEGFR2 and caspase-3 expressions

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Annals of Eye Science 2019年第1期4卷 81-86页

作者： Yang Gao Xiangchao Yao Yujun Li chen Cao Chulong Huang zeli.Guo Yandong Wang Department of Pharmacy&State Key Laboratory of Ophthalmology Zhongshan Ophthalmological CenterSun Yat-sen UniversityGuangzhou 510501China

Background:To investigate the effect of sirolimus(SRL)eye drops on acute alkali-burn-induced corneal neovascularization(CNV)and explore its possible ***:A total of 57 male Sprague-Dawley rats weighing 160-180 g were randomly divided into four groups including a normal control group(NC group,n=12),an untreated alkali-burned model control group(MC group,n=15),a blank eye drop treatment group(BT group,n=15),and an SRL eye drop treatment group(ST group,n=15).Corneal inflammation and CNV were observed and scored under a slit-lamp microscope 3,7,and 14 days after alkali *** rats were randomly sacrificed in each group before modeling and 3,7,14 days after modeling,and the corneas of right eyes were harvested for Western blotting to compare the expression levels of VEGFR2 and ***:Corneal inflammation scoring showed that the corneal edema and conjunctival congestion were severe in the MC,BT,and ST groups 1 day after alkali exposure but were alleviated at day *** corneal transparency was significantly higher in the ST group than in the MC and BT groups at days 7(F=9.77,P0.05;F=0.98,P>0.05).The corneal expression of VEGFR2 became significantly higher in the MC and BT groups than in the ST group 3,7,and 14 days after alkali exposure,and there were significant differences in relative gray-scale values among these groups(day 3:F=32.16,P<0.01;day 7:F=85.96,P<0.01;day 14:F=57.68,P<0.01).The increase in the corneal expression of

关键词： Sirolimus(SRL) corneal neovascularization(CNV) eye drops rats

The microbial community,nutrient supply and crop yields differ along a potassium fertilizer gradient under wheat-maize double-cropping systems

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Journal of Integrative Agriculture 2024年第10期23卷 3592-3609页

作者： zeli.Li Fuli Fang Liang Wu Feng Gao Mingyang Li Benhang Li Kaidi Wu Xiaomin Hu Shuo Wang Zhanbo Wei Qi chen Min Zhang Zhiguang Liu Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection College of Resources andEnvironmentLinyi UniversityLinyi 276000China National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources College of Resources and theEnvironmentShandong Agricultural UniversityTai’an 271018China Key Laboratory of Crop Specific Fertilizer Ministry of Agriculture and Rural Affairs/Xinyangfeng Agricultural Technology Co.Ltd.Jingmen 448001China Institute of Applied Ecology Chinese Academy of SciencesShenyang 110000China

Soil microorganisms play critical roles in ecosystem ***,the relative impact of the potassium(K)fertilizer gradient on the microbial community in wheat-maize double-cropping systems remains *** this long-term field experiment(2008-2019),we researched bacterial and fungal diversity,composition,and community assemblage in the soil along a K fertilizer gradient in the wheat season(K0,no K fertilizer;K1,45 kg ha^(-1) K_(2)O;K_(2),90 kg ha^(-1)K_(2)O;K3,135 kg ha^(-1)K_(2)O)and in the maize season(K0,no K fertilizer;K_(1),150 kg ha^(-1) K_(2)O;K_(2),300 kg ha^(-1)K_(2)O;K_(3),450 kg ha^(-1)K_(2)O)using bacterial 16S rRNA and fungal internally transcribed spacer(ITS)*** observed that environmental variables,such as mean annual soil temperature(MAT)and precipitation,available K,ammonium,nitrate,and organic matter,impacted the soil bacterial and fungal communities,and their impacts varied with fertilizer treatments and crop ***,the relative abundance of bacteria involved in soil nutrient transformation(phylum Actinobacteria and class Alphaproteobacteria)in the wheat season was significantly increased compared to the maize season,and the optimal K fertilizer dosage(K2 treatment)boosted the relative bacterial abundance of soil nutrient transformation(genus Lactobacillus)and soil denitrification(phylum Proteobacteria)bacteria in the wheat *** abundance of the soil bacterial community promoting root growth and nutrient absorption(genus Herbaspirillum)in the maize season was improved compared to the wheat season,and the K2 treatment enhanced the bacterial abundance of soil nutrient transformation(genus MND1)and soil nitrogen cycling(genus Nitrospira)genera in the maize *** results indicated that the bacterial and fungal communities in the double-cropping system exhibited variable sensitivities and assembly mechanisms along a K fertilizer gradient,and microhabitats explained the largest amount of the variation in crop yields,a

关键词： potassium fertilizer gradient microbial community wheat-maize double cropping climate change yield

Emerging probing perspective of two-dimensional materials physics:terahertz emission spectroscopy

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Light(Science & Applications) 2024年第7期13卷 1278-1298页

作者： Yifei Wu Yuqi Wang Di Bao Xiaonan Deng Simian Zhang Lin Yu-chun Shengxian Ke Jianing Liu Yingjie Liu zeli.Wang Pingren Ham Andrew Hanna Jiaming Pan Xinyue Hu Zhengcao Li Ji Zhou chen Wang State Key Laboratory of New Ceramics and Fine Processing Key Laboratory of Advanced Materials of Ministry of EducationSchool of Materials Science and EngineeringTsinghua University100084 BeijingChina Beijing Advanced Innovation Center for Integrated Circuits 100084 BeijingChina

Terahertz(THz)emission spectroscopy(TES)has emerged as a highly effective and versatile technique for investigating the photoelectric properties of diverse materials and nonlinear physical processes in the past few ***,research on two-dimensional(2D)materials has experienced substantial growth due to their atomically thin structures,exceptional mechanical and optoelectronic properties,and the potential for applications in flexible electronics,sensing,and ***,these materials offer advantages such as tunable bandgap,high carrier mobility,wideband optical absorption,and relatively short carrier *** applying TES to investigate the 2D materials,their interfaces and heterostructures,rich information about the interplay among photons,charges,phonons and spins can be unfolded,which provides fundamental understanding for future *** it is timely to review the nonlinear processes underlying THz emission in 2D materials including optical rectification,photon-drag,high-order harmonic generation and spin-to-charge conversion,showcasing the rich diversity of the TES employed to unravel the complex nature of these *** applications based on THz emissions,such as THz lasers,ultrafast imaging and biosensors,are also *** further,we analyzed the unique advantages of spintronic terahertz emitters and the future technological advancements in the development of new THz generation mechanisms leading to advanced THz sources characterized by wide bandwidth,high power and integration,suitable for industrial and commercial *** continuous advancement and integration of TES with the study of 2D materials and heterostructures promise to revolutionize research in different areas,including basic materials physics,novel optoelectronic devices,and chips for post-Moore’s era.

关键词： optoelectronic versatile exceptional

Clinical Evaluation of Hepatic Fibrosis in Chinese Patients with Nonalcoholic Fatty Liver Disease with FibroScan

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Chinese Medicine 2015年第2期6卷 115-123页

作者： zeli.Gao Xiaoli Lin Guoyu chen Jieru Ji Mingfeng Tang Xiaotong He Qinghui Xiong Ming Li Department of Gastroenterology People’s Hospital of Pudong New Area Shanghai China Laboratory of Innovative Medicine Hong Kong

Aim: The clinical value of FibroScan in evaluation of hepatic fibrosis was assessed in Chinese patients with nonalcoholic fatty liver disease (NAFLD). Methods: Liver stiffness and other NAFLD related variables were measured in NAFLD patients with either elevated or normal hyaluronic acid (HA) levels, and in healthy volunteers respectively. Moreover, hepatic fibrosis rat model was used for the correlation analysis between the measured liver elasticity and its corresponding pathological changes. Results: The severity of NAFLD in patients was positively correlated with both HA level and FibroScan values suggesting that fibrosis occured along with the progression of NAFLD. Interestingly, the FibroScan value was found to change at an earlier stage of the disease than that of HA level. The mean liver elasticity in the sampling volume of the region of interest in experimental rats, which were subject to the induction of liver fibrosis using peritoneal injection of carbon tetrachloride (CCl4) for 6 or 9 weeks respectively, was measured using Fibroscan. The examination of pathological changes of these experimental rats demonstrated the positive correlation of the measured elasticity values with the extent (severity) of the corresponding pathological changes in the rats of 6 weeks post induction of liver fibrosis with a moderate liver fibrosis, or 9 weeks with a severe liver fibrosis. The average liver stiffness for the normal liver (S0) was 4.51 ± 0.82 kPa, for moderate liver fibrosis (S2) was 6.91 ± 1.32 kPa, and for severe liver fibrosis (S3) 9.62 ± 1.82 kPa. Conclusion: FibroScan can be used to objectively and quantitatively identify the trend in the changing stiffness of the liver and noninvasively detect the development of liver fibrosis.

关键词： FibroScan Nonalcoholic Fatty Liver Disease Hyaluronic Acid Ultrasound Elastography

Sirolimus eye drops inhibit acute alkali-burn-induced corneal neovascularization by regulating VEGFR2 and caspase-3 expressions

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Sirolimus eye drops inhibit acute alkali-burn-induced cornea...